The present invention relates to a scan driver, an electro-optical device, and a drive method.
A liquid crystal panel is used as a display section of an electronic instrument such as a portable telephone. In recent years, a still image and a video image which are valuable as information have been distributed accompanying widespread use of portable telephones, and an increase in the image quality of the liquid crystal panel has been demanded.
An active matrix type liquid crystal panel using a thin-film transistor (hereinafter abbreviated as “TFT”) is known as a liquid crystal panel which realizes an increase in the image quality of a display section of an electronic instrument. The active matrix type liquid crystal panel using the TFT realizes high response time and high contrast in comparison with a simple matrix liquid crystal panel using a dynamically driven super twisted nematic (STN) liquid crystal, and is suitable for displaying a video image or the like (see Japanese Patent Application Laid-open No. 2002-351412).
However, since the active matrix type liquid crystal panel using the TFT consumes a large amount of electric power, power consumption must be reduced in order to employ the active matrix type liquid crystal panel as a display section of a battery-driven portable electronic instrument such as a portable telephone. An interlaced drive is known to reduce power consumption. A comb-tooth drive which reduces a coloring error of each display pixel is also known. The interlaced drive is a drive method suitable for displaying a still image, since the image quality is decreased when applied to a video image.
Therefore, a driver circuit which can deal with various drive methods such as a normal drive, interlaced drive, and comb-tooth drive is demanded for a display panel (liquid crystal panel, for example) which displays a still image and a video image.